Can marriage be happy without having kids?

I’m 26, my husband is 27. We’ve known each other for three years, lived together for two years and we’ve been married for six months. We’re not rich, but we’re a happy couple and have some savings.

Our parents live in the countryside and they want grandchildren soon. We also love children and want to have a child.

However, my husband understands my health condition. He often says that children are a gift from God, and it’s fine if we don’t get to receive that gift. We can work, then travel together after retirement and take care of each other when we’re sick.

I always feel insecure because I’m not able to be a mother. And even if my condition gets better, I might be too old to have a baby by that point.

I’m worried that without a child, our marriage will be affected, and if my parents-in-law can’t sympathize, we’ll end up in conflict.

What should we do to maintain a happy marriage without children?